- 您现在的位置：买卖IC网 > PDF目录44986 > LT3688HFE#PBF (LINEAR TECHNOLOGY CORP) SWITCHING REGULATOR, PDSO24 PDF资料下载
参数资料
| 型号： | LT3688HFE#PBF |
| 厂商： | LINEAR TECHNOLOGY CORP |
| 元件分类： | 稳压器 |
| 英文描述： | SWITCHING REGULATOR, PDSO24 |
| 封装： | LEAD FREE, PLASTIC, TSSOP-24 |
| 文件页数： | 17/28页 |
| 文件大小： | 415K |
| 代理商： | LT3688HFE#PBF |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页当前第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页
LT3688
24
3688f
Figure 14. Top Layer PCB Layout in the LT3688
Demonstration Board
APPLICATIONS INFORMATION
3688 F14
these components should be as small as possible. These
components, along with the inductor and output capacitor,
should be placed on the same side of the circuit board.
Place a local, unbroken ground plane below these com-
ponents. The SW and BST nodes should be as small as
possible. Finally, keep the FB node small so that the ground
traces will shield them from the SW and BST nodes.
The exposed pad on the bottom of the package must be
soldered to ground so that the pad acts as a heat sink. To
keep thermal resistance low, extend the ground plane as
much as possible, and add thermal vias under and near
the LT3688 to additional ground planes within the circuit
board and on the bottom side.
High Temperature Considerations
The PCB must provide heat sinking to keep the LT3688
cool. The exposed pad on the bottom of the package must
be soldered to a ground plane. This ground should be tied
to large copper layers below with thermal vias; these lay-
ers will spread the heat dissipated by the LT3688. Placing
additional vias can reduce thermal resistance further. With
these steps, the thermal resistance from die (or junction)
to ambient can be reduced to
θJA = 40°C/W or less. With
100 LFPM airow, this resistance can fall by another 25%.
Further increases in airow will lead to lower thermal re-
sistance. Because of the large output current capability of
the LT3688, it is possible to dissipate enough heat to raise
the junction temperature beyond the absolute maximum
of 125°C (150°C for H Grade). When operating at high
ambient temperatures, the maximum load current should
be derated as the ambient temperature approaches 125°C
(150°C for H Grade). Power dissipation within the LT3688
can be estimated by calculating the total power loss from
an efciency measurement and subtracting the catch diode
loss. The die temperature is calculated by multiplying the
LT3688 power dissipation by the thermal resistance from
junction-to-ambient. Thermal resistance depends on the
layout of the circuit board, but values from 30°C/W to
60°C/W are typical. Die temperature rise was measured
on a 4-layer, 5cm 7.5cm circuit board in still air at a load
current of 0.8A (fSW = 800kHz). For a 12V input to 3.3V
output the die temperature elevation above ambient was
14°C; for 12VIN to 5VOUT the rise was 15°C and for 12VIN
to 5VOUT and 3.3VOUT the rise was 30°C.
Other Linear Technology Publications
Application Notes 19, 35 and 44 contain more detailed
descriptions and design information for buck regulators
and other switching regulators. The LT1376 data sheet
has a more extensive discussion of output ripple, loop
compensation and stability testing. Design Note 318
shows how to generate a bipolar output supply using a
buck regulator.
VIN
3688 F13
EN/UVLO
BOOST
SW
LTC3688
BIAS
GND
DA
D4
FB
VIN
VOUT
+
Figure 13. Diode D4 Prevents a Shorted Input from Discharging
a Backup Battery Tied to the Output; It Also Protects the Circuit
from a Reversed Input. The LT3688 Runs Only When the Input
Is Present
相关PDF资料 |
PDF描述 |
|---|---|
| LT3688HFE#TRPBF | SWITCHING REGULATOR, PDSO24 |
| LT3689IUD-5#PBF | 1.95 A SWITCHING REGULATOR, 2160 kHz SWITCHING FREQ-MAX, PQCC16 |
| LT3689EMSE-5#TRPBF | 1.95 A SWITCHING REGULATOR, 2160 kHz SWITCHING FREQ-MAX, PDSO16 |
| LT3689EUD-5#TRPBF | 1.95 A SWITCHING REGULATOR, 2160 kHz SWITCHING FREQ-MAX, PQCC16 |
| LT3689EMSE-5#PBF | 1.95 A SWITCHING REGULATOR, 2160 kHz SWITCHING FREQ-MAX, PDSO16 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LT3688IFE#PBF | 功能描述:IC REG BUCK ADJ 0.8A DL 24TSSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 产品培训模块:MIC23xxx HyperLight Load™ Regulators 标准包装:5,000 系列:HyperLight Load® 类型:降压（降压） 输出类型:固定 输出数:1 输出电压:1.8V 输入电压:2.7 V ~ 5.5 V PWM 型:混合物 频率 - 开关:4MHz 电流 - 输出:2A 同步整流器:是 工作温度:-40°C ~ 125°C 安装类型:表面贴装 封装/外壳:8-VFDFN 裸露焊盘，8-MLF? 包装:带卷 (TR) 供应商设备封装:8-MLF?（2x2） 产品目录页面:1094 (CN2011-ZH PDF) 其它名称:576-3303-2 |
| LT3688IFE#TRPBF | 功能描述:IC REG BUCK ADJ 0.8A DL 24TSSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 设计资源:Design Support Tool 标准包装:1 系列:- 类型:升压（升压） 输出类型:固定 输出数:1 输出电压:3V 输入电压:0.75 V ~ 2 V PWM 型:- 频率 - 开关:- 电流 - 输出:100mA 同步整流器:是 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:SOT-23-5 细型，TSOT-23-5 包装:剪切带 (CT) 供应商设备封装:TSOT-23-5 其它名称:AS1323-BTTT-30CT |
| LT3688IFEPBF | 制造商:LINER 制造商全称:Linear Technology 功能描述:Dual 800mA Step-Down Switching Regulator with Power-On Reset |
| LT3688IUF#PBF | 功能描述:IC REG BUCK ADJ 0.8A DL 24QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 产品培训模块:MIC23xxx HyperLight Load™ Regulators 标准包装:5,000 系列:HyperLight Load® 类型:降压（降压） 输出类型:固定 输出数:1 输出电压:1.8V 输入电压:2.7 V ~ 5.5 V PWM 型:混合物 频率 - 开关:4MHz 电流 - 输出:2A 同步整流器:是 工作温度:-40°C ~ 125°C 安装类型:表面贴装 封装/外壳:8-VFDFN 裸露焊盘，8-MLF? 包装:带卷 (TR) 供应商设备封装:8-MLF?（2x2） 产品目录页面:1094 (CN2011-ZH PDF) 其它名称:576-3303-2 |
| LT3688IUF#TRPBF | 功能描述:IC REG BUCK ADJ 0.8A DL 24QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 设计资源:Design Support Tool 标准包装:1 系列:- 类型:升压（升压） 输出类型:固定 输出数:1 输出电压:3V 输入电压:0.75 V ~ 2 V PWM 型:- 频率 - 开关:- 电流 - 输出:100mA 同步整流器:是 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:SOT-23-5 细型，TSOT-23-5 包装:剪切带 (CT) 供应商设备封装:TSOT-23-5 其它名称:AS1323-BTTT-30CT |
发布紧急采购，3分钟左右您将得到回复。